Currently none of the potential treatments for HIV-1 have proven to be both non-toxic and effective in long-term use. Lamivudine (3TC) has been shown to be a potent, relatively non-toxic, selective inhibitor of HIV replication in vitro. Initial clinical studies have demonstrated a favorable safety profile. As well as having a low toxicity profile, initial clinical studies have shown that 3TC is effective in improving the prognostic marker profile of HIV-infected patients, which may be indicative of clinical benefit.